Issue 691: To join a congregation is only allowed during the recitation or while bowing. So, if a person misses the bow of the Imam, they must join the congregation in the next Rak'at, and even if a person joins the congregation while bowing, it will be accounted as one Rak'at.
Issue 692: There are different ways to join a congregation:
Translator’s Preface
سائٹ کي سروسز
تفکر
